Oil reclaimer



Feb. 26, 1929.

C. VAN BRUNT ET AL OIL RECLAIMER originai Filed July s,

1922 2 Sheets-Sheet 7'0 RESERVO/R inventors Charles Van Brul-1t.

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Feb. 26, 1929. 1,703,648

. C. VAN BRUNT ET AL OIL RECLAIMER original Filed July 1922 2 Sheets-sneer. 2

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UNITED STATES l 1,703,648 PATENT OFFICE. i

CHARLES VAN BRUNT, OF SCIIENECTADY, AND PHILIP S, MILLER, OF SCOTIA, NEW YORK, ASSIGNORS TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

oIL RECLAIMER.

Original application filed July 3, 1922, Serial-No. 572,601, and in Great Britain November 17, 1921.

' Dvidetland this application filed 'November 20, 1924. Serial No. 751,129l

This applicationis a division of our application Ser. No. 572,601 filed July 3, 1922, which is in turn av continuation-in part of an application Serial No. 484,202, filed July 12, 1921.

3 The present invention relates to the purification of li uids and particularly to the reclamation of lubricating oil which has been used in the crank case of an internal combustion engine, or under any other conditions which reducev its viscosity and impair its lubricating qualities... Our invention comprises a method which makes it possible to re move volatilizable impurities" from oil, and ina single and expeditious way to restore 'the viscosity or bod of used oil to substantially its original con ition so that it will be equal or even superior in serviceability'to unused oil. The apparatus for practicing our invention is automatic in operatiomis free from fire hazard, and is simple in construction so .that it may bereadily operated even by unskilled labor. This apparatus is claimed .in the copending application Serial No.

` 572,601 of which the a division.

In the crank case of internal combustion engines, particularly under the conditions encountered by automobile engines, the lubricant becomes contaminated 'both with solid matter and diluted by unburnt fuel constituents. This dilution of the oil lowers its lubricating and pistonl sealing'value.' Our present invention relates,v to the removal of the diluents in the oil. These diluents are completely miscible with the heavier lubricating oil, and therefore could be removed by ordinary heating of the oil in bulk only. at a dangerously high temperature and anuneconomical'expenditure of time and energy.

In accordance with one feature of our invention, we have provided a method whereby the rate of evaporation is so greatlyaccelerated that only a moderate temperature is required for a commercially -useful rate of reclamation.

In accordance with vanother feature of our invention the oil to be purified in the form of a thin turbulent film, is subjected to a draft or current or air, ror other gas, which carries away the vapor from the surface of the film. In accordance with another feature of oui invention we have provided an evaporator which subjects the oil to a progressively present application ,is

,feed the. Qil in SuchV @mnner that there@ of feed also will be independent of variations Y of the head of the oil in the storage tank and feed pipe.`

Our invention will be better understood from the following description taken in connection with the accompanying drawings,-

and its scopewill be pointed out in the appended claims.

Referring to the accompanying drawings, Fig. 1 is, a' perspective `view of a Apreferred form of apparatus for practicing our invention, a part of the housingbeing shown brokenY away; Fig. 2 shows in perspective a complete outfit including a -feed device; Fig. 3 is a `ragmental view showing the preferred constructionf of an evaporator for use in our oil recovery device; Fig. 4e is a vertical section of our feed device; Fig. 5 is a vertical section of another form of apparatus for practicing our invention; Fig. 6 is a perspective view of the apparatus shownin Fig. 5; Figs. 7 and 8 constitute respectively perspective -views of the spreader and heater used in the apparatus shown in Figs. 5 and 6.

Referring to the drawing, the apparatus shown in Fig. 1 comprises a distributing device 1,- into which oil to be reclaimed is fed by a tube 2., The oil is discharged and distributed upon each side of an evaporator 4 by ducts 3 which preferably are of capillary dimensions. The construction of the evaporator. will be hereinafter more fully described, particularly connection with Fig. 3. After passing over 'the 'surface of the evaporator, where it is substantially freed from diluents, the oil is dischargedinto a receiving storage tank 5 from which it may be withdrawn by a cock 6, as shown in Fi 2. The volatilized constituents from the oil arecarried away by a current of air, or other gas, which enters the. apertures 7 becomes cated in contact withthe evaporator, and

therefore rises andl escapes through a vent pipe 8. The function of the draft, produced in this way (or in any other waythatcircumstances may indicate) and flowing in a counter direction with respect to the oil current is of prime importance in that it greatly expedites evaporation by keeping the partial pressureof the vapors of the diluents down, and thus renders this operation practical at a comparatively low temperature. The dilution of the vapors attendant upon this feature has also the important effect of rendering the gasiiied diluent non-inflammable.

As shown in F ig. 1, the evaporator is plateshaped and therefore adapted to bev used in apparatus of large capacity in any desired number of units placed side by side. is described in detail hereinafter a particular form of evaporator adapted to be used in the practice of our invention, but We wish it to be understood that various other conf structions may be employed to accomplish the desired' result, tle essential feature being l tinuously moving film.

the provision of*meansf'wlrerebyA the'oilto -be reclaimed shall be spread in a moving film of minute thickness over a'heatedvsurface, the

film being subjected as it moves along to sufficient heat toI volatilizevthe diluents in,y the oil, or whatever liquid is to be purified.

The evaporator as best shown inl-Fig. 3

comprises an electric resistance heater 10 supported on a sheet of insulating materialll, for example, by securing-the resistance wire under ears 12cutfeutof the insulating sheet material and bent back upon the same.'

Upon each side of the heater wire thus .mounted are placed sheets of insulating material 13 so as to secure the resistor between sheets of insulation. Upon each side of the .insulated resistor are vplaced in turn plates v 14, 14 of suitable sheet metal.

These plates may be secured in place by marginal stiifening strips soldered at the edges and secured ,by bolts 15 to the side walls 16 of the reclaiming chamber. The sidewalls 16 of the reclaiming chamber preferably are double to provide heat insulation. Upon the surface -of these sheet metal plates is secured some means for Aguiding theoil received from the distributing device 1 over the entire surface of the heated metal plates 14, 14', as a con- VVe prefer to use for thisv purpose a rectieulated material, such as .a wire gauze 17, which vis secured to the surface of the sheet metal by welding or 'riveting so as to provide aA plurality of capillary spaces into which the oil will run and therefore be spread uniformly over the heated surface as a line network of tiny streams with a film of varying thickness between them instead of following certain narrow paths which would otherwise be t-he case.

In order to secure the greatest eiicieney,

the wire gauze 17 should be so attached tothe There The heater which may be of any desired form is shown in Fig. 3 asmarwire bent back and forth upon itself, the turns of the zigzag being placed more closely adjacent to one another at the bottom than at the top so as to heat the lower` part of the plates 14 and 14 to a higher temperature than theupper part. rlhis affords a very compact construction in which the film of oil isbrought Ainto very close contact with the heated surface over a relatively large area so that the heatis applied uniformly to all parts of the oil film, lthe oil with the above described construction, being subjected to a gradually andfuniformly increasingtemperature. lreferably, we profrom about 120 C.- at the top of the plates to about 150 C. at the bottom of the plates.

becomes less, as a result both of their decreasing eoncentration and of the increasing boiling point of the residual constituents. To counteract this the temperature encountered becomes increasingly higher as the oil flows downward. In other words, the rising temperature gradient from the top of the evaporator downwardly, counteracts a tendency for the evaporation of vdiluents to slow down, asthe oil film passes over the evaporator. I Although the dimensions of the evaporator may be varied to some extent, an increase of the length of path over which the oil may flow is of little advantage beyond a limit determined by the nature of the oil and its content of diluents. l/Vhen using a plate-shaped evaporator, as shown in Fig. 1, for the reclamation of oil taken from the crank case of anv automobile, we prefer to use units having a height of about 12 inches, the width being determined by convenience. The oil flow preferably occurs at a rate of about 3% gallons per square foot of evaporator Isurface per day of 24 hours. This rate is illustrative only, because, while, as explained below, it is not designed to be adjustable at will by the operator, but to remain fixed, at least over long periods, it will depend upon certain factors which practice and demand may impose; forexample, the well known seasonal` '90 vide for a steady increase of temperature' variations and requirements in crank case lubrication.

With a fixed orifice, the head and the rate o'f oil flow will vary rapidly withthe degree ya liquid which is not readily volatile from a concentration A to a` concentration B, is proportional to log. A minus log. B, is in favor of an approximate independence ,of the rate of rectification and the degree of dilution.f

For example, the time required to reduce a diluent in the oil from ten and one-half parts to ten parts is less than the time required to reduce the concentration from one and onehalf to one per cent. p

In' accordance with this mathematical function,'the rate of evaporation increases enormously` with the concentration of the diluent above a certain point, and conversely, decreases to a similar extent with the diminution of the concentration below a certain point so that a considerable increase in the dilution of the oil will not greatly affect the total time of its substantial removal.

A further consideration of a device of the present character' which is intended to be operated by unskilled labor, or at least, by labor having by training and inclination little interest in the operation of an oil reclaimer, is that the operation ofthe device shouldbe wholly automatic and should require no adjustment of feed valves for oils of different viscosity. Still another consid-v eration in favorof an automatic rate of feed, which cannot be readily changed by the operator, is the fact' that it removes the possibility of increasing the rateof operation at the expense of the character of the productl l/Ve have therefore provided, as illustrated in Fig. 2, an apparatus whereby the feed takes place in a fixed and definite manner, which is obtained by providing for a fixed low head of oil and a feed of oil by displacement with water supplied through a capillary orifice.

Fig. 2 shows in perspective the oil reclaimer, designated by R, receiving oil from an intermediate storage tank T, which in turn receives the impure oil through a pipe 20A leading to a reservoir -(not shown) into which the impure oil may be dumped at any time and accumulated. The intermediate tank T may be of small capacity, say, froma quart upward. It contains a float 21 (see also Fig. 4) connected to a valve in the receiving pipe 20.' When the fioat 21 is in the position shown anda quantity of oil is contained in the tank T, the oil is displaced by water received from'Y an adjoining tank 22 communieating with the main tank, and receiving Water at a constant rate through an opening of capillary dimensions, for example, a pipe 23i The Water floats off the oil at the same rate through a pipe24 into-the receiving pipe 2 of the oil reclaimer. A vent 25 is provided to prevent the pipe 24 acting as a Siphon. In order to avoid the Water following the oil and fiowing off through the pipe 24 into the oil reclaimer, a siphon 26 has been provided through which the water will escape when it has reached a certain level.

` The operation of tlie -feed device will best be understood by reference to Fig. 4. Suppose the tank 22 to be llcd with water up to the level a and the communicating ta'nk 27 to contain Water up to the level .b and oil from level b to the level c. As the oil is lighter than water the -upper level (Lof the Water in the tank 22 will be below the level c. Water is 'admitted to the tank 22 at a constant rate through `the capillary tube 23 in which throttling 1s obtained by len th rather than by constriction, and which t erefore, is less vlikely to plug up than a cock or needle valve. As the How of water is constant, the oil-displacement is constant, regardless of changing viscosity of the oil and of changing head. As the oil and water interface at b rises, the level a also rises, until finally the level of waterbecomes high enough to start the siphon 26. The siphon 26 empties the tank 22 at a greater rate than oil can be supplied by the supply pipe 2U, so that the sipvhon breaks before oil can follow the Water through the same. The tank 27 thenfills with oil until the supply is shut off 'by the float operated valve 28. The oil feed by displacement with Water then is repeated. Since the capillary distributing ducts 3, (Fig. 1) are of fixed dimensions, a standpipe islprovided to permit oil of varying-viscosities fed at a constant primary rate, as above indicated, to automatically find a level at which their discharge through the ducts 3 equals this rate, regardless of their viscosities.

Figs. 5 and 6 illustrate somewhat simpler embodiments ofour invention in which the standard heater lamps are used in place of the plate heater shown in Figs. 1 and These heaters, as illustrated in F ig. 8, comprise a bullo 30 containing the usual incandescent filament 31 connected to wires'leading to the standard screw socket 32. The exterior surface ofthe heater lamp may be roughened or frosted, as indicated in Figs. 5 or 6. ,The heater lamps are arranged to be inserted into standard sockets 33, 34, which are fixed to the side Wall of a chamber 35, adjoining the main'chamber 36 in which the oil reclamation takes place. We prefer to provide al plurality of lamps located one above the other, the resistance and Wattage of the heatersV being so chosen that the lower heater operates at a somewhat higher temperature than the upper heater` For example, the upper heater ma operate'at a temperature o 110 to 125 and the lower heater may operate at a tempcrature of 135 to 150 C. The heaters con-v veniently are connected electrically in'series by the conductors 37, 38, and 39, to supply mains 40. Surrounding the heaters are oil distributors 41 consisting of wire gauze, or

vother suitable recti'culated material.

f 6. These deiectors are spaced away from the heaters and are so shaped as to conform with the general surface configuration of the heaters, thereby directing the airlcu'rrents entering through the lower draft holes45 over t-he surface of the oil film in order to carry away the vapors arising from the surface of the oil. The vapor laden'air escapes through the upper draft holes 46. The supply tube 47of the storage tank 48 is provided with a tightly iitting cap 49. Air can be admitted to the space above the oil onlyv by a tube 50 which terminates near the bottom of the tank. By this means the oil flow from tank 48 through the feed pipe 51 may beegulated to proceed at a substantially constant rate as the oil level in the tank falls. This regulation'is also assisted by a stopcock 52 in the pipe 51.

The device shown in Fig. 6, corresponds very closely to the device shown in Fig. 5, except that a chamber 53 is provided intermediate the oil tank 48 and the evaporating chamber 36 to prevent undue heating of the oil in the chamber 48. A double row of ventilating holes 54 is providedin the walls of this intermediate chamber 53. Fig. 6 also y.shows the stop cock 52 provided with an eX- ternal handle 55.

When the iiow of oil has been adjusted to a suitable rate the door 56 ofthe draft cham- I We mean by the appended claims to cover i modifications and equivalents coming within the scope and-spirit of our invention. For

example, when in the claims we have specifically referred to currents of air, we mean 'also to cover gases other than air used for the same purpose.

What we claim as new and desire to secure by Letters Patent of the United States, is,-

1. The method of purifying used lubricating oil by the removal of diluents which consists in causing said oil to ow downwardly as afine network of tiny streams over a substantially vertical evaporator provided with numerous capillary spaces and causing the temperature of said evap'orator to increase progressively from about 120 C. at the top to about 150 C. at the bottom,and directing a current of' air upwardly over saidoil lm, thereby carrying away vapors arising from the oil iilm, and collecting the oil after passing over said evaporator.

2. The method of freeing used lubricating oil from vdiluents contained therein whereby its viscosity is lowered which A consists in spreading said oil as a film constituted by a fine net-work of tiny streams,V heating said film to a temperature which is suiciently high to volatilize said diluents therefrom, and which increases in the direction of flow of said streams, and separately carrying away the vaporized diluents and the rectified oil.

In witness whereof we have hereunto set our hands this 19th day of November, 1924.

` CHARLES VAN BRUNT.

PHILIP s. MILLER. 

